#include "flutter_window.h"

#include <optional>
#include <tchar.h>

#include "flutter/generated_plugin_registrant.h"

FlutterWindow::FlutterWindow(const flutter::DartProject& project)
    : project_(project) {}

FlutterWindow::~FlutterWindow() {}

bool FlutterWindow::OnCreate() {
  if (!Win32Window::OnCreate()) {
    return false;
  }

  RECT frame = GetClientArea();

  // The size here must match the window dimensions to avoid unnecessary surface
  // creation / destruction in the startup path.
  flutter_controller_ = std::make_unique<flutter::FlutterViewController>(
      frame.right - frame.left, frame.bottom - frame.top, project_);
  // Ensure that basic setup of the controller was successful.
  if (!flutter_controller_->engine() || !flutter_controller_->view()) {
    return false;
  }
  RegisterPlugins(flutter_controller_->engine());
  SetChildContent(flutter_controller_->view()->GetNativeWindow());

  flutter_controller_->engine()->SetNextFrameCallback([&]() {
    this->Show();
  });

  // Flutter can complete the first frame before the "show window" callback is
  // registered. The following call ensures a frame is pending to ensure the
  // window is shown. It is a no-op if the first frame hasn't completed yet.
  flutter_controller_->ForceRedraw();

  return true;
}

void FlutterWindow::OnDestroy() {
  if (flutter_controller_) {
    flutter_controller_ = nullptr;
  }

  Win32Window::OnDestroy();
}

LRESULT
FlutterWindow::MessageHandler(HWND hwnd, UINT const message,
                              WPARAM const wparam,
                              LPARAM const lparam) noexcept {
  // Process keyboard messages
  if (message == WM_KEYDOWN || message == WM_SYSKEYDOWN) {
    // Handle Ctrl+C (copy)
    if (wparam == 'C' && (GetKeyState(VK_CONTROL) & 0x8000)) {
      // Simulate standard copy operation
      // First check if there is text selected
      HWND focusedWindow = GetFocus();
      if (focusedWindow) {
        // Send copy command
        SendMessage(focusedWindow, WM_COPY, 0, 0);
        return 0; // Message processed
      }
    }
    
    // Handle Ctrl+V (paste)
    if (wparam == 'V' && (GetKeyState(VK_CONTROL) & 0x8000)) {
      // Simulate standard paste operation
      HWND focusedWindow = GetFocus();
      if (focusedWindow) {
        // Send paste command
        SendMessage(focusedWindow, WM_PASTE, 0, 0);
        return 0; // Message processed
      }
    }
    
    // Handle backspace key
    if (wparam == VK_BACK) {
      // Get current focused window
      HWND focusedWindow = GetFocus();
      if (focusedWindow) {
        // Check if it's a text input control
        TCHAR className[256];
        GetClassName(focusedWindow, className, 256);
        
        // If it's a text input control, send backspace key message
        if (_tcscmp(className, TEXT("EDIT")) == 0 || 
            _tcscmp(className, TEXT("RichEdit20W")) == 0 ||
            _tcscmp(className, TEXT("RichEdit50W")) == 0) {
          // Send backspace key message
          SendMessage(focusedWindow, WM_KEYDOWN, VK_BACK, 0);
          return 0; // Message processed
        }
      }
      // If not a text input control, let Flutter handle it
    }
  }
  
  // Give Flutter, including plugins, an opportunity to handle window messages.
  if (flutter_controller_) {
    std::optional<LRESULT> result =
        flutter_controller_->HandleTopLevelWindowProc(hwnd, message, wparam,
                                                      lparam);
    if (result) {
      return *result;
    }
  }

  switch (message) {
    case WM_FONTCHANGE:
      flutter_controller_->engine()->ReloadSystemFonts();
      break;
  }

  return Win32Window::MessageHandler(hwnd, message, wparam, lparam);
}
